The present invention relates to an implant provided with attachment and hole-insert parts which have surfaces with different degrees of finishing and/or degrees of roughness and/or porosities. It also relates to a method for establishing different degrees of finishing and/or degrees of machining and/or porosities on outer surfaces of an implant with attachment and hole-insert parts. The invention also relates to an arrangement for providing a range of implants which are optimized for different dental situations.
It is already known to use implants which have upper parts for attachment of spacer elements or other superstructures and, below said upper parts, lower parts which are intended to be inserted in a hole in the bone, for example in the jaw bone or tooth bone. The attachment part in question is arranged on the jaw bone which, after the implant has become incorporated, is exposed for connection of the spacer or superstructure in question. Said lower parts can be designed with threads and it is possible to use straight cylindrical thread portions which at the bottom merge into a cone-shaped threaded portion at the tip of the implant.
For examples of implants, reference may be made inter alia to WO 97/43976 and WO 97/03621.
It is, also already known to provide the different surfaces of the implant with different finishes and/or machine treatments and/or porosities. In this connection reference may be made to, inter alia, the Swedish applications 9901971-3, 9901973-9 and 9901974-7 filed by the same applicant as the present application. Reference may also be made to U.S. Pat. Nos. 5,571,017, 5,829,978, 5,842,865, 5,885,079, 5,947,735 and 5,989,027.
From the above references it is already known to use different degrees of porosity on the surfaces in question. There are different opinions concerning the sizes of the pores and their applications. Thus, it has previously been proposed that the surface of the attachment part be made of a machined smooth surface, while the threads on the lower parts of the implant can be made with porosities of different sizes, i.e. different degrees of roughness. From the above references it is also already known to provide different parts along the longitudinal extent of the implant with different degrees of porosity. It is known that one zone with a first degree of porosity on the surface changes abruptly into a second or adjacent zone having a second degree of porosity.